目的 探讨氧化苦参碱通过调节miR-155-5p表达对胃癌细胞的增殖、凋亡、迁移、侵袭中的作用和其潜在机制。方法 使用TRIzol法提取组织标本和细胞系的总RNA，检测胃癌组织与癌旁组织中的miR-155-5p表达情况。采用qRT-PCR评估miR-155-5p在人胃癌细胞系（SGC7901、MGC803）与正常胃黏膜上皮（GES-1、AGS）细胞中的表达情况。将MGC803分为空白组、转染错义序列siRNA组、miR-155-5p模拟物组、miR-155-5p抑制剂组、氧化苦参碱（100 μmol/L）组、氧化苦参碱＋miR-155-5p模拟物组。采用MTT法观察不同干预下胃癌细胞的生长抑制作用，用细胞集落形成试验检测不同干预下胃癌细胞的增殖情况。用流式细胞技术分析不同干预对胃癌细胞凋亡的影响。Transwell法检测不同干预后胃癌细胞的迁移、侵袭情况。蛋白质印迹法检测MGC803细胞中Claudin 1、c-Myc、cyclin D1、Bcl-2、Caspase-3蛋白的相对表达量。结果 与癌旁组织和胃黏膜细胞（GES-1、AGS）相比，在胃癌组织和胃癌细胞系（SGC7901、MGC803）中miR-155-5p相对表达量升高（P＜0.001）。而氧化苦参碱通过调节miR-155-5p表达抑制胃癌细胞生长。MTT实验表明，miR-155-5p模拟物的转染后MGC803细胞活力显著增加，而氧化苦参碱可显著抑制胃癌细胞、转染和miR-155-5p模拟物的细胞活力（P＜0.001）。与空白组、错义序列siRNA组相比，miR-155-5p模拟物转染后MGC803细胞活力显著增加，细胞集落生成增加，而氧化苦参碱可显著抑制胃癌细胞的活力和转染miR-155-5p模拟物的细胞活力，及细胞集落生成数（P＜0.001）。miR-155-5p-模拟物组的细胞迁移和侵袭细胞数显著增加、凋亡比例降低，而氧化苦参碱组和miR-155-5p-抑制剂组细胞迁移和侵袭细胞数量降低、凋亡比例升高（P＜0.001）。miR-155-5p模拟组的Claudin 1、c-Myc、Cyclin D1、Bcl-2相对表达量增加，而Caspase-3相对表达量降低（P＜0.01、0.001）。而miR-155-5p抑制剂组、氧化苦参碱组和氧化苦参碱＋miR-155-5p抑制剂组的Claudin 1、c-Myc、Cyclin D1、Bcl-2表达较miR-155-5p模拟组显著下降，Caspase-3表达增加（P＜0.001）。结论 miR-155-5p可能是胃癌的治疗靶点，氧化苦参碱可通过miR-155-5p的调节作用发挥抗肿瘤作用。

Objective To investigate the role and potential mechanism of oxymatrine in regulating the expression of miR-155-5p in the proliferation, apoptosis, migration, and invasion of gastric cancer cells. Method Total RNA from tissue specimens and cell lines was extracted by TRIzol method, to detect the expression of miR-155-5p in gastric cancer tissues and adjacent tissues. The expression of miR-155-5p in human gastric cancer cell lines (SGC7901, MGC803) and normal gastric mucosal epithelial cells (GES-1, AGS) was evaluated by qRT-PCR. MGC803 was divided into blank group, transfected missense sequence siRNA group, miR-155-5p simulant group, miR-155-5p inhibitor group, oxymatrine (100 μmol/L) group, and oxymatrine + miR-155-5p mimics group. MTT assay was used to observe the growth inhibition of gastric cancer cells under different interventions, and colony formation assay was used to detect the proliferation of gastric cancer cells under different interventions. Effects of different interventions on apoptosis of gastric cancer cells were analyzed by flow cytometry. The migration and invasion of gastric cancer cells after different interventions were detected by Transwell method. The relative expression levels of Claudin 1, c-Myc, Cyclin D1, Bcl-2, and Caspase-3 in MGC803 cells were detected by Western blotting. Results The relative expression of miR-155-5p was increased in gastric cancer tissues and gastric cancer cell lines (SGC7901, MGC803) compared with para-cancerous tissues and gastric mucosa cells (GES-1, AGS) (P < 0.001). Oxymatrine inhibited the growth of gastric cancer cells by regulating the expression of miR-155-5p. MTT assay showed that MGC803 cell viability was significantly increased after transfection with miR-155-5p mimicry, and the cell viability of gastric cancer cells, transfection and miR-155-5p mimicry was significantly inhibited by oxymatrine (P < 0.001). Compared with blank group and missense sequence siRNA group, MGC803 cell viability and colony generation were significantly increased after transfection with miR-155-5p mimics, while oxymatrine significantly inhibited the viability of gastric cancer cells, the cell viability and colony generation number of transfected miR-155-5p mimics (P < 0.001). The number of cell migration and invasion cells increased significantly and the proportion of apoptosis decreased in the miR-155-5p simulant group, while the number of cell migration and invasion cells decreased and the proportion of apoptosis increased in the oxymatrine and miR-155-5p- inhibitor groups (P < 0.001). The relative expressions of Claudin 1, c-Myc, Cyclin D1, and Bcl-2 in miR-155-5p simulant group were increased, while the relative expressions of Caspase-3 were decreased (P < 0.01, 0.001). The expressions of Claudin 1, c-Myc, Cyclin D1, and Bcl-2 in miR-155-5p inhibitor group, oxymatrine group, and oxymatrine + miR-155-5p inhibitor group were significantly decreased compared with those in miR-155-5p simulant group, and the expression of Caspase-3 was increased (P < 0.001). Conclusion MiR-155-5p may be a therapeutic target for gastric cancer, and oxymatrine can exert anti-tumor effects through the regulatory effect of miR-155-5p.

R966；R979.1

三二〇一医院科研基金资助项目（3201yk201530）